A Systematic Narrative Review of the Evidence for Labeling of Natural Health Products and Dietary Supplements

Abstract

Background: It is not clear what information is needed on labels of natural health products and dietary supplements to support informed consumer choice and use of these products. Aim: The purpose of this review was to explore if/how label information impacts consumer decision-making about food, over-The-counter drugs, and natural health products/dietary supplements and to make recommendations about how this evidence may be applied to natural health products/dietary supplements. Method: A narrative analysis of a systematic review was performed. Medline and Embase databases were systematically searched to identify relevant studies from 1985 to February 2018 for all available English-language articles. This was supplemented with hand searches of the reference lists of review articles. Results: One hundred and fifty-one studies met the inclusion criteria, and after excluding review articles, 127 were included in the analysis. The findings from the studies were categorized into three main themes: (1) impact of labeling on consumer behavior (the majority of studies found that changes in label format or information had little to no effect on consumer behavior such as purchasing); (2) consumer comprehension of label information (significant proportions of consumers were unable to accurately interpret information found on natural health product/dietary supplement, over-The-counter medication, or food labels); and (3) label formatting/design, including standardization of information in fact tables (standardization, front-of-pack, and contrasting color panels were preferred and best attracted consumer attention). Conclusions: Many consumers did not regularly read product labels, nor understand the information they read on those labels. There was evidence that consistency of information was preferred by many consumers. Font size clearly impacted consumers' ability to read and understand the information on labels and this needed to be balanced with the amount of information required on labels. There was evidence that symbols that are simple and used sparingly are helpful in providing direction to consumers. Finally, regardless of what information was on the label, changing labels alone was unlikely to have a significant impact on consumer behavior.